Re: [gentoo-dev] [PATCH] boost-utils.eclass -- for building against newest boost.

[Tiziano Müller]

Am Dienstag, den 28.08.2012, 10:06 +0200 schrieb Michał Górny:
> On Tue, 28 Aug 2012 06:26:02 +0200
> Arfrever Frehtes Taifersar Arahesis <arfrever.fta@×××××.com> wrote:
>
> > 2012-08-28 00:19:28 Michał Górny napisał(a):
> > > --- /dev/null
> > > +++ b/gx86/eclass/boost-utils.eclass
> > > @@ -0,0 +1,43 @@
> > > +# Copyright 1999-2012 Gentoo Foundation
> > > +# Distributed under the terms of the GNU General Public License v2
> > > +# $Header: $
> > > +
> > > +if [[ ! ${_BOOST_ECLASS} ]]; then
> > > +
> > > +# @ECLASS: boost-utils.eclass
> > > +# @MAINTAINER:
> > > +# mgorny@g.o
> >
> > It is better to copy list of maintainers from
> > gentoo-x86/dev-libs/boost/metadata.xml.
> >
> > > +# @BLURB: helper functions for packages using Boost C++ library
> > > +# @DESCRIPTION:
> > > +# Helper functions to be used when building packages using the
> > > Boost C++ +# library collection.
> > > +
> > > +case ${EAPI:-0} in
> > > +	0|1|2|3|4) ;;
> > > +	*) die "${ECLASS}.eclass API in EAPI ${EAPI} not yet
> > > established." +esac
> >
> > Please accept all EAPIs.
>
> These are EAPIs which are allowed throughout the tree, sorry. Feel free
> to ping Council about adding non-standard EAPIs to eclasses.
>
> > > +inherit versionator
> > > +
> > > +# @FUNCTION: boost-utils_get_best_slot
> > > +# @DESCRIPTION:
> > > +# Get newest SLOT (major version) of Boost.
> > > +boost-utils_get_best_slot() {
> > > +	local pkg=dev-libs/boost
> > > +	local atom=$(best_version ${pkg})
> > > +	get_version_component_range 1-2 ${atom#${pkg}}
> > > +}
> > > +
> > > +# @FUNCTION: boost-utils_get_includedir
> > > +# @DESCRIPTION:
> > > +# Get correct includedir for best Boost version. Outputs the sole
> > > path +# (without -I).
> > > +boost-utils_get_includedir() {
> > > +	local slot=$(boost-utils_get_best_slot)
> > > +	has "${EAPI:-0}" 0 1 2 && ! use prefix && EPREFIX=
> > > +
> > > +	echo -n "${EPREFIX}/usr/include/boost-${slot/./_}"
> > > +}
> >
> > There needs to be a way to specify maximal accepted slot of Boost.
> > Examples of some possibilities:
> > * BOOST_MAX_SLOT="1.49" global variable
> > * '--max 1.49' arguments for boost-utils_get_* functions
>
> I'd rather wait with that till Tiziano expresses his opinion. I think
> the policy ought to be 'always prefer newest version' but I guess
> that's hard with boost.
>

one of the points of having a slotted boost (besides solving the rebuild
when API/ABI breakages occur) is that a package may also use an older
boost slot (currently it only would make sense if we'd backport the
glibc-2.16 patches but that's a different story). So I'd prefer if we'd
have a BOOST_MAX_SLOT variable.